The invention relates to an adjuster for a vehicle seat, in particular for an automobile seat, wherein the adjuster includes a toothed element and a pawl, both of which are mounted for moving relative to a bearing element, and the pawl cooperates with the toothed element to restrict movement of the toothed element relative to the bearing element.
A known adjuster of this kind, which is used as a linear adjuster for an automobile seat, comprises a rack, which is a toothed element, and an elongate housing, which is a bearing element. The rack and housing are adapted for sliding movement relative to each other in the unlocked state of the adjuster, thereby changing the overall length of the adjuster. In the housing, a pawl or rocking arm is mounted for rotation about a pin. The pawl is adapted for engaging with its teeth the teeth of the rack, so that the adjuster is locked. In this locked position, the pawl is held by a cam or cam plate. A disadvantage with the use of this known adjuster is that the adjustment of the overall length of the adjuster can occur only in certain steps, which are predetermined by the tooth pitch of the rack, and the adjuster cannot engage when a tooth comes to lie on a tooth in a tip-to-tip fashion upon engagement of the pawl.
The present invention solves the above and other problems by providing an adjuster including a toothed element mounted for moving relative to a bearing element, and a pawl floatably supported on the bearing element so that the pawl can cooperate with the toothed element to restrict movement of the toothed element relative to the bearing element. In accordance with one aspect of the present invention, the adjuster is incorporated into an automobile seat, or the like.
As a result of floatably supporting the pawl on the bearing element, it is capable of pivoting relative to the bearing element in its pivoting direction and is also movable in a further direction relative to the bearing element. Because of the floatably supporting, the pawl is capable of performing a translational motion (or a motion in the circumferential direction), and can slide at least a short distance along the toothed element, so that when it engages, it is possible to avoid or eliminate a positioning of tooth on tooth in a tip-to-tip fashion. A preferred floating support that is efficient to produce is partially provided by an elongate hole, which can be provided in the pawl or in the bearing element.
Preferably, the floating support is controlled by an eccentric element, which converts the translational portion of the pawl motion into a rotation, which is simpler to interrupt, for example, by a locking element that can lock the eccentric element. It is preferred to construct the eccentric element in one piece or in two pieces. While a one-piece eccentric element is more cost-favorable to manufacture, a bipartite eccentric element can encircle the bearing of the pawl in the locked state and adjust it free of play. Preferably, the locking element engages the eccentric element by means of a gear tooth system, which is finer than a gear tooth system between the toothed element and the pawl. This provides a locking engagement which has less steps and is even almost stepless in the case of a very fine gear tooth system.
In a preferred construction, the pawl is adapted for movement by means of a control member at least in part along the toothed element. A positioning of a tooth on a tooth, in a tip-to-tip fashion, upon engagement will automatically be removed during the locking procedure. The first engaging tooth of the pawl, i.e., the tooth with the shortest distance from the bearing element, may be made somewhat shorter than the other teeth, so that upon obliquely impacting, it comes to engage between two teeth of the toothed element.
The adjuster of the present invention may be designed and constructed either as a linear adjuster, for example, as a longitudinal or a vertical adjuster, or as a rotary adjuster, for example, as a locking mechanism. This adjuster can be used in particular in an automobile seat. As one example, when constructed as a longitudinal adjuster, the toothed element and the housing for supporting the pawl can each be integrated in separate rails. In this instance, the rails extend within each other.